<div class="refentry"><a id="glStencilMaskSeparate"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glStencilMaskSeparate — control the front and/or back writing of individual bits in the stencil planes</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glStencilMaskSeparate</strong>(</code></td><td>GLenum <var class="pdparam">face</var>, </td></tr><tr><td> </td><td>GLuint <var class="pdparam">mask</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>face</code></em></span></dt><dd><p>
                    Specifies whether the front and/or back stencil writemask is updated.
                    Three symbolic constants are valid:
                    <code class="constant">GL_FRONT</code>,
                    <code class="constant">GL_BACK</code>, and
                    <code class="constant">GL_FRONT_AND_BACK</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>mask</code></em></span></dt><dd><p>
                    Specifies a bit mask to enable and disable writing of individual bits
                    in the stencil planes.
                    Initially, the mask is all 1's.
                </p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glStencilMaskSeparate</code> controls the writing of individual bits in the stencil planes.
            The least significant
            <math overflow="scroll"><mi mathvariant="italic">n</mi></math>
            bits of <em class="parameter"><code>mask</code></em>,
            where
            <math overflow="scroll"><mi mathvariant="italic">n</mi></math>
            is the number of bits in the stencil buffer,
            specify a mask.
            Where a 1 appears in the mask,
            it's possible to write to the corresponding bit in the stencil buffer.
            Where a 0 appears,
            the corresponding bit is write-protected.
            Initially, all bits are enabled for writing.
        </p><p>
            There can be two separate <em class="parameter"><code>mask</code></em> writemasks; one affects back-facing polygons, and the other
            affects front-facing polygons as well as other non-polygon primitives.
            <a class="citerefentry" href="glStencilMask"><span class="citerefentry"><span class="refentrytitle">glStencilMask</span></span></a> sets both front
            and back stencil writemasks to the same values, as if
            <a class="citerefentry" href="glStencilMaskSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilMaskSeparate</span></span></a> were called
            with <em class="parameter"><code>face</code></em> set to <code class="constant">GL_FRONT_AND_BACK</code>.
        </p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>face</code></em> is
            not <code class="constant">GL_FRONT</code>, <code class="constant">GL_BACK</code>, or
            <code class="constant">GL_FRONT_AND_BACK</code>.
        </p></div><div class="refsect1"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument
            <code class="constant">GL_STENCIL_WRITEMASK</code>, <code class="constant">GL_STENCIL_BACK_WRITEMASK</code>,
            or <code class="constant">GL_STENCIL_BITS</code>
        </p></div>
        {$pipelinestall}{$examples}
        <div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glColorMask"><span class="citerefentry"><span class="refentrytitle">glColorMask</span></span></a>,
            <a class="citerefentry" href="glDepthMask"><span class="citerefentry"><span class="refentrytitle">glDepthMask</span></span></a>,
            <a class="citerefentry" href="glStencilFunc"><span class="citerefentry"><span class="refentrytitle">glStencilFunc</span></span></a>,
            <a class="citerefentry" href="glStencilFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilFuncSeparate</span></span></a>,
            <a class="citerefentry" href="glStencilMask"><span class="citerefentry"><span class="refentrytitle">glStencilMask</span></span></a>,
            <a class="citerefentry" href="glStencilOp"><span class="citerefentry"><span class="refentrytitle">glStencilOp</span></span></a>,
            <a class="citerefentry" href="glStencilOpSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilOpSeparate</span></span></a>
        </p></div><div class="refsect1"><div id="Copyright"><h2>Copyright</h2><p>
            Copyright © 2006 Khronos Group.
            This material may be distributed subject to the terms and conditions set forth in
            the Open Publication License, v 1.0, 8 June 1999.
            <a class="ulink" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.
        </p></div></div></div>
